排除日期時間對象而忽略一年？

Question

我有一個存儲在datetime對象中的生日列表。如何使用只有month和day參數的Python對它們進行排序呢？

例如，

[ 
    datetime.datetime(1983, 1, 1, 0, 0) 
    datetime.datetime(1996, 1, 13, 0 ,0) 
    datetime.datetime(1976, 2, 6, 0, 0) 
    ... 
] 

謝謝！ :)

Answer 1

您可以使用month和day來創建可用於排序的值：

birthdays.sort(key = lambda d: (d.month, d.day)) 

Answer 2

l.sort(key = lambda x: x.timetuple()[1:3]) 

Answer 3

如果日期存儲爲字符串，你說他們都沒有，雖然它看起來他們是，你可以使用dateutil的解析器：

>>> from dateutil.parser import parse 
>>> from pprint import pprint 
>>> bd = ['February 6, 1976','January 13, 1996','January 1, 1983'] 
>>> bd = [parse(i) for i in bd] 
>>> pprint(bd) 
[datetime.datetime(1976, 2, 6, 0, 0), 
datetime.datetime(1996, 1, 13, 0, 0), 
datetime.datetime(1983, 1, 1, 0, 0)] 
>>> bd.sort(key = lambda d: (d.month, d.day)) # from sth's answer 
>>> pprint(bd) 
[datetime.datetime(1983, 1, 1, 0, 0), 
datetime.datetime(1996, 1, 13, 0, 0), 
datetime.datetime(1976, 2, 6, 0, 0)] 

如果你的日期是在不同的格式，你可以給模糊解析一個鏡頭：

>>> bd = [parse(i,fuzzy=True) for i in bd] # replace line 4 above with this line